As a fighter pilot tortured and kept prisoner during the Vietnam War, Bale had to transform his body while staying in shape for the more action-oriented parts of the movie. Despite this, he expressed frustration when talking to the AV Club about how the physical challenges of the shoot took most of the attention during the press junket.
"With Rescue Dawn, people asked me various questions on [the physicality], and I attempted to steer them back toward the movie as a whole, rather than any one particular point about the movie. Because otherwise, unfortunately, it could end up seeming like some kind of a gimmick.
In an interview with Collider, director Werner Herzog revealed that he had lost some weight in solidarity with Bale's regimen.
"When Christian lost weight, I said to him, 'Christian, out of solidarity I'm losing half the amount of pounds that you are losing' and I actually did."